Glycol tank - cap will not fully tighten and glycol level problem?

jplusj

I am hearing my Alde system gurgling, so I checked the expansion tank.  I found that the fluid was at the minimum mark and the filling cap could not be screwed on very tightly.  The threads on the tank [or cap] appeared to be stripped.  I can certainly pour more glycol in the tank, but I am concerned about having the cap be securely tightened.  I didn't find any leakage; however, it may have evaporated.  Any ideas on what is going on and some solutions?     
Just some background information:  I had my T@B 320 in for service at the dealership and to have the Alde system to be repaired.  Well, the dealer fixed the Alde hot water problem but not the heating.  I had to take it back.  The dealership seemed to solve the heating problem by filling the glycol tank.  Apparently, the tank was empty.  I have had my T@B for just over 2 years, so it sounds like the glycol should be replaced.         

MuttonChops

@jplusj ;
The Adle CAP on my unit is also weird.  Starts to screw on then pops like the threads are bad.  That said have never found it completely off the tank ever after 40-mile gravel / washboard roads.

My Adle seems to need a cup or two of fluid every 3-months or so . . . no idea how it disappears.

Plus being lazy or ???  will most likely delay changing the fluid until it is 5-years old.
BTW, The 'standard change' that NüCamp does only changes a gallon or so of fluid.  To do a 100% change takes more work and equipment.
Edited 01-17-21;  See @mona post & @Sharon_is_SAM reply to mona below

pthomas745

For the gurgling, you might want to check the pump setting.  Here are a bunch of images from threads that will show you what to look for. 

https://www.google.com/search?q=gurgling+glycol+site:tab-rv.vanillacommunity.com&client=firefox-b-1-d&sxsrf=ALeKk02L4eNSzIELVxur_0teg_X3_-i7kg:1610854511815&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjzj9jXhKLuAhXyHDQIHb6uB0wQ_AUoAnoECAoQBA&biw=1920&bih=1098

Sharon_is_SAM

@jplusj - Sounds like they didn’t add enough glycol.  Depending on how empty your glycol lines were, you may have air in your lines resulting in the glycol level dropping in the tank.  Add more glycol, then turn up your glycol pump speed to “5” to help get any air out of the system.  Return the pump speed to “1.5” and try heating again.  

mona

I keep reading periodically, that the NuCamp only does a partial glycol exchange. I had my glycol exchanged at NuCamp for the second time in December. Per Austin, NuCamp does not do a partial exchange. NuCamp uses the pump and does a full exchange. 

Sharon_is_SAM

@mona - correct.  Now they do a full exchange.  In the past, they did not have the pump and they did a gravity drain.

PNWtabber

Glad to see this discussion as I just added more fluid to the expansion tank in my T@B yesterday (second time since September) and noticed the issue with threading the cap back on the tank.  I assumed it was me doing something wrong, LOL.  Must just be the plastic threads.

mntrails

I wrapped electrical tape around the threads of the glycol resevoir in a clockwise direction. I think it was 2 wraps only and stretched slightly. The cap now threads on fine and tightens. It seemed a lot easier at the time than going back to NuCamp.

Dona

i called Truma tech support about the loose cap thinking it was designed to be a sloppy fit and he said no... it should seat and close:  tighten...gently.

4ncar

I went to top off this afternoon also. I was curious about this issue, after reading it. I was removing the cap, and thought to myself, “what’s the issue?” When I went to put the lid back on, I experianced what has been spoken of. The fix, at least for me, is to pres down on he lid as you screw it in. The threads will catch correctly. This worked for me, without any further mods or gyrations.

SolidCamper

I love the way people help each other and share their information on this forum.  I hate to come across as negative in this post about our TAB trailers that we all so love, - but frankly- I can't believe how inaccessible the 2020 Tab320S  glycol tank is, and how difficult it is to work with.

Besides the fact that its location is not mentioned in their manual- once you do finally find it, it takes some serious acrobatics to get to it, to judge the glycol level, and to fill it to the correct level, with some improvised dipstick.  I understand that nuCamp has relocated the tank in the 2021 Tab320S, but what about us !

Its even more frustrating that all the manuals keep saying how important it is to religiously monitor this level, but the tank's location makes that is so hard to do just that.

I had an idea to rout in a hole in the wood panel that lies in front of the tank, the size of an oversized electrical switch cover, or core in a 4-in dia. hole the size of a plastic snap-in black cover. Then I could just pop off the cover, see the level and know what's up. This will need to be done very carefully with a temporary protective steel plate squeezed in front of the tank to prevent it from being punctured during the proposed surgery.

Before I go ahead with this, I'm curious if others have had similar ideas, or have come up with different creative ideas to overcome this difficult situation.  Also, please tell me If you think that what I am planning to do is a mistake, and if so, please tell me why. Thank you.

jkjenn

The tank has been moved to much more accessible location in the 2021 models.

db_cooper

There's so little space in the 320's I understand why it's where it is in the older trailers.  And for me, giving up the under bed storage for the AC and having the glycol tank in a better location aren't improvements.  Where the AC is now is where the glycol lines run to bench seat radiators, and it's where I dry ski boots, clothes, gloves, etc.  I don't think there's a similar space in the new ones that would work for that. 

When you're working with such limited square footage, absolutely everything is a compromise.

That said, we made the glycol tank easier to get to in our 2015 by removing the screw that held down the back cover of the headboard, and mounted some velcro to hold in place.  Now I can just open it and take a look without tools, and we prop it open in really cold weather to let the heat out.   Not sure if that would work for a 2020.

fstop32

@SolidCamper, I'll be adding a "view port" to my 2015 but I have the advantage of having disassembled the rear half of my T@b so I can throw the headboard on the workbench and port it.
A hole saw sounds precarious to me, I always have a hard time controlling them plus the drill bit extends deeper than the saw.  I'm a router lover.

SolidCamper

@fstop32,  As I crawled into that space this afternoon to start drilling, I looked around, noted all the pocket screws,  and thought that it just might be easier to just disassemble the rear shelving as you appear to have done. But I forged ahead, installed my thin back plate and drilled away. One little central 1/4 hole is done-  I have to wait a week or so as my hole saws and flush-trim router bits are at a job a couple of hours away.

What was it like to disassemble the rear cabinetry? Other than the accessible pocket screws, are there any other difficult-to-access connections? How long did it take you. I may abandon my drill in place plan and use your approach if its straight-forward and just a couple of hours of work. Thanks 

ScottG

@SolidCamper, a view portal sounds like a reasonable idea to me. I would probably have done the same thing if I had a newer model with the side cabinetry. (I just have a simple back shelf like @db_cooper, and mine fits firmly in place without screws or Velcro.)

Another option (maybe a moot point now) might be to replace the panel screws with threaded inserts and thumb screws to facilitate tooless removal.

Regardless, while keeping an eye on your glycol level is well advised, it probably isn't something you need to obsess about. I check mine periodically, and I've had to top it up exactly once in six years. More top-ups might be required if your run the cabin heat regularly.

fstop32

@SolidCamper, I'm not familiar with the 2020 model and it's tank location but on my 2015 the main thing in your way is the headboard.  As I mentioned I had a major corrosion problem so I was going way deeper to remove hoses and convectors.  In the 2015 the rear convectors are mounted to the back side of the headboard as are 2 of the 4 screws holding the tank in place.  Disconnecting those pieces in a gentle way so as not to damage the convectors or stress hose joints will be a pain and probably a lot more time than a couple of hours.  I tend to have to measure my project time in days, but I'm uh, methodical     If your 2020 tank location is similar to mine I'd suggest the router, and a trim router for it's smaller size would work best.  You'll probably need to remove the rear bench back to get enough working space.  With the router you can control the bit depth and if you make a jig you can clamp in place your router can't cut into something unintended.  If the tank is up against the back of the headboard removing the screws holding the tank will give you enough space to keep the bit from hitting it.
I used a felt tip marker to make the "min" and "max" lines more readable on my tank which helps too.
Let me know how it goes and if you have any more questions! 

fstop32

@SolidCamper, I picked up this link (thank you @Bayliss) with pics of a 2020 mod in progress.  I think it will be helpful.

https://tab-rv.vanillacommunity.com/discussion/13070/permanent-side-to-side-sleeping-for-t-b-320-s/p1 

I had to chuckle when I saw where the convectors are mounted...that's exactly where I decided to put mine instead of back on the back side of the headboard.

fstop32

@SolidCamper, check out the 3rd picture down in that link, it will show you what your dealing with in there.  I think you will definitely need to loosen the tank so you won't damage it.

ScottG

fstop32 said:

...
I had to chuckle when I saw where the convectors are mounted...that's exactly where I decided to put mine instead of back on the back side of the headboard.

I noticed that, too. I wonder if that is to provide additional clearance for the storage insert. It also may reflect that the flow of air over the convectors is different in the cubbie-equipped models. The heat outflow along the back wall seems superior to the older slots that tend to get covered by bedding.

A popular mod before the change was to cut vent holes in back shelf so the heat could rise straight up and out.

fstop32

@ScottG I think you are correct on the different location of the convectors.  I was trying to find a way to make that shelf deeper so you could store more stuff and not have it flying all over the camper during towing.  Where our convectors (now only yours  ) are located prevents one from lowering the shelf.  I too think the heated air flow in that design is superior to the 2015 era.

SolidCamper

@fstop32 Thanks for the links and your comments. Seems like anyway you cut it, there will be pain. Based on what you describe about removing the surrounding cabinetry, I think that my best bet will be to do what I first considered. I will use a small plunge router where I can dial in the depth, take a deep breath, and rout away.

There is now already in place a perfect-sized hardened protective steel plate- a small old handsaw blade that just "threaded the needle" between the plastic tank and the unfinished plywood. (I knew I was holding onto that old blade for something!:)

I think that I will shoot for a hole diameter that I can cover up with an easily pulled out soffit vent. This will cover the hole and also achieve some flow of heated air when covered.

If I go with the circle, there are a few few options. Thought you'd get a kick out of my idea to use a sawed-off ring from a PVC toilet flange as my control template. Then go with a router bushing against the PVC ring.

Thanks again for your helpful comments and support. Your ideas and thoughts are always welcome.

@ScottG.. I hope that you are right that one need not get obsessed about the glycol level. I had some crazy things happen after 9 days and nights of constant Alde use recently out on the road. My glycol spilled onto my friends driveway two weeks ago, probably thru the exp tank overflow,  and my glycol level, when finally checked was way down, with nothing in the tank. After some unexplained fluctuations, the glycol level seems to have settled down. 

I wouldn't go to the trouble of installing the port if, once you removed the wooden triangular side panel, you could actually see the level. I'm literally using "finger braille" to find my min and max, and a wooden dipstick to judge the level- the whole thing is nuts. All that being said, I'm sure that you are right and that it will not really be an issue over time--  unless of course, I heaven-forbid puncture the tank trying to install the port  

Have a nice weekend.

MuttonChops

mntrails said:

I wrapped electrical tape around the threads of the glycol reservoir in a clockwise direction. I think it was 2 wraps only and stretched slightly. The cap now threads on fine and tightens.

WOW

Great idea and so simple.  While I did 'awesome flag' your January comment just got around to adding some tape today.

That darn Cap has Never screwed on soooo easy.

Big Thanks!

rcarlson1957

@fstop32  Any trick to getting the ALDE fluid out of the hoses and radiators when doing hose maintenance? I I'm  going to replace a cracked expansion tank, add some elbows for strain relief, and replace the manual bleed valve with one with a 24 in clear hose. I opened the ALDE drain before I took the old tank out but assume there is a whole lot of fluid still in the radiators and hoses. I have already removed the old expansion tank. Just trying to keep the mess to a minimum. 

Denny16

The Alde drain under the trailer is the lowest point drain.  You need to put some air pressure in the feed tube for the expansion, to push more fluid out of,the heat exchangers and lower tubes.  See Chainging Alde Fluid previous discussion for details.
 Cheers 

fstop32

@rcarlson1957, good ideas on the elbows for strain relief and the longer bleeder valve hose (I went with a 12" version).  Pic below shows some of my "elbow work".  I know the elbows create a bit more resistance to flow but I felt the trade off of eliminating the pinch points of tight bends on straight pieces of hose was more than worth it.

I noticed you've already pulled the tank and opened the low point drain.   When I pulled my system apart I ran into the same issue of pockets of glycol that couldn't gravity drain.  In the driver side bench I unscrewed the convectors so I could raise them high enough to drain, then removed the hoses and plugged them.  The passenger side was a different matter since the glycol lines ran to floor level and prevented my raising the convectors high enough to do any good.  My system had so much corrosion that I had to replace everything but the boiler.  
As deeply as it sounds like you're getting into yours I would suggest a couple of ideas.  One, I added a second gravity drain in the passenger side rear bench area.  I located it in the mirror location as the existing driver side drain (see pic).  

This eliminated the pocket of glycol that can't make it over to just the one drain.  Secondly I positioned my new hoses and convectors with a slight slope so when I pop the drains all the glycol will flow to one of the two drain positions (I positioned the hoses/convectors with the trailer perfectly level).  Instead of mounting a pair of convectors one on top of the other I separated the input/output ends of the convectors by about 1/4" to create the intended slope.  I used quite a few hose mounting brackets to maintain the intended slopes of the hoses throughout the camper.  Net effect is when the camper is set level there are no "level" positions for any of the convectors or hoses.  When I refilled my system I pumped the glycol through the new passenger side drain.  If my "slope theory" was executed properly that should have allowed the system to fill and let all the air be pushed up toward the tank.  I had very little burping after running the glycol pump on high to force any remaining air from the system.

@SolidCamper, I do like the PVC router guide bushing idea!  I've found creating jigs to be as much fun as the actual woodworking process!  I decided to forego the reservoir viewing port on mine since I ended up totally rebuilding the rear cabinet area.  You can look at my post of that woodworking project in my post "Back Shelf Rebuild or Post Corrosion Fallout".

rcarlson1957

@fstop32 , looks great! On the new T@Bs they have 2 ALDE drains right next to each other. Makes it easy for fluid changeouts. I have a storage door where you hoses go on the passenger side but still a great idea.